Very low bit rate DCT coding by spectral similarity analysis

Conventional transform coding schemes such as JPEG process the spectrum signal in a block by block manner due to its simple manipulation; nevertheless it does not consider the similarity of different spectrums. The proposed method devises a translation function, which reorganizes the individual spectrum data to generate the global spectrums according to their frequency band. Among those different bands, high similarity characteristic is existing. Our algorithm analyzes the similarity of those different spectrum bands to reduce the bit rate of transmission or storage. Simulations are carried to many different nature images to demonstrate that the proposed method can improves the performances when compared with other existing transform coding schemes especially at very low bit rate (below 0.25 bpp) requirement.